Name: Gerrit V.
ProgramYear: 2006
Submit Date: May 28, 2006
Review Date: May 30, 2006

Energy Supply to a Martian Base A self-sufficient colony on Mars is a dream for scientists who want to learn more about space. It would be one of the first footholds humans have in conquering the Final Frontier, and provide unheard-of opportunities for research in a myriad of fields. However, creating such a colony requires an extremely intricate infrastructure capable of supporting the colony- both the machines and the inhabitants. The most obvious type of energy required for a colony, on Mars or elsewhere, is the production of electricity. It is required to power the crucial computer systems and machines that allow humans to live and work on a planet which cannot support life. There are several options for energy production on Mars. The first is a nuclear generator, which has the advantages of being a long-term, high-yield energy source. However, a nuclear generator is a highly advanced machine, which would have to be manufactured on Earth before being brought to Mars. Assuming the Mars colony is self-sufficient, it would be difficult to repair eventual technical failures the generator might have. Also uranium, the element used as fuel in such a generator, is not readily available on Mars. The colony’s uranium stock would also, then, be dependent on supplies from Earth. Solar energy is another obvious energy source, which will be the primary energy producer for the colony. Cheap and reliable, solar energy has been used by NASA to provide power for many space missions. The average energy consumption per capita of developed countries in 2001 was approximately 5350 kWh per year, or 14.66 kWh per day per capita (colonists on Mars are most likely more efficient with energy use, but this presents a liberal estimate). The colony needs power 24 hours a day, but allowing for only 14 hours of operation (sunrise to sunset) during a Martian day, you calculate that [14.66 x 24 / 14] = 25.25 kilowatts of installed power per colonist is required. Assuming a colony population of 200, 5050 kilowatts of installed power must be produced by solar panels to suit the electricity needs of the colony. The average solar irradiance at the top of the Martian atmosphere falls between 495 and 725 W/m2. Assuming the Martian colony is located between 20 and 40 degrees longitude (to take advantage of the warmer temperatures and to avoid an extended lightless winter, as would be encountered at the poles), the light encounters an average of 150 W/m2 solar insolation as it reaches the surface. This presents an average solar irradiance at the Martian surface of between 345 and 575 W/m2. The most efficient solar panels, advanced triple-junction cells, can reach 30% efficiency- but allowing for less-than-ideal conditions such as dust, we will use a more conservative 25%. That is to say, they can produce between 85 and 140 watts per square-meter of solar panels on the surface of Mars. In order to produce 5050 kW under even the most adverse conditions, a Martian colony will need approximately 59500 square-meters of solar panels, or 14.75 acres of solar power. Wind energy is another option. The velocity of atmospheric winds on Mars range from 1-50 m/s (during global dust storms), but are generally between 2-10 m/s. This could present the opportunity to generate electricity by wind turbines, which would supplement the energy production of the solar fields. Turbines are far more complex and might require difficult repairs, so like nuclear generators the colony might be dependent on Earth for the manufacturing of spare parts. However, they do present an alternative source of energy not dependent on the sun. Compared to producing electricity for the machine systems of the colony, procuring energy for the colonists themselves will be far more complex. The human biochemistry is an elaborate balance which has been accustomed to Earth from the very beginning. Certain minerals and nutrients it requires to function are either difficult to gather or simply do not exist in adequate amounts on Mars. The two most important chemicals for Martian colonists are oxygen and water. Unfortunately, neither is available with nearly the convenience that it is on earth. To this end, colonists will need to produce the oxygen and water themselves. Oxygen production is relatively simple, as humans have developed many methods for extracting oxygen from a variety of places. Also, Mars has oxygen locked away in multiple chemicals available in abundance. Carbon dioxide, which composes 95.32% of the Martian atmosphere, and a large variety of oxides (such as silicon dioxide, SiO2) are available from the soil. ‘Cooking’ the oxygen out of the soil is quite possible, by heating the soil in the presence of hydrogen to form water and metal oxides, then reducing those compounds further to obtain breathable oxygen gas. Using this method on gathered Martian regolith and air would produce sufficient quantities of breathable oxygen, which is a process requiring large amounts of energy. However, respiration is a continual process. Rather than constantly extracting oxygen, the colony will also need an oxygen regeneration system. With chemical converters to serve as a backup in the event of an emergency, biological catalysts are the best choice for a colony. Due to the availability of CO2 in the Martian atmosphere (95%), the supply of CO2 would not be a limiting factor to the production of oxygen. Besides oxygen generation, biological converters can also provide a renewable food source for the colonists. Some of the energy for the growth of these organisms would come from the ambient light on Mars, but an expansion of the energy-producing solar fields might be required to continue growth when ambient light is limited, such as during a dust storm. Cyanobacteria are one of the primary oxygen-producing organisms on Earth, and have multiple advantages in microgravity use over plants. As simpler organisms which can inhabit a huge range of environments, cyanobacteria are better suited to microgravity and living in a Martian colony. They are more efficient, by weight, at converting carbon dioxide into oxygen, and can be completely recycled into food products. Certain species, such as Lyngbya majuscula, have properties that go far beyond simple oxygen production. L. majusula has hundreds of biologically active compounds, including anti-HIV, anti-cancer and antibacterial products. This has enormous pharmaceutical value, especially for an isolated colony. In order to determine the amount of cyanobacteria required for oxygen production, experiments would have to be conducted to determine the oxygen production rate of a cyanobacterial colony in an environment simulating a Martian colony. The rate could then be applied to the rate of consumption of the colony, with the realization that oxygen will only be a portion of the internal atmosphere. Water is the second most important chemical compound in a Martian colony. It can either be created by heating metallic oxides in the Martian soil in the presence of oxygen- as described above- or by mining it from deposits in the Martian soil. Geological analysts of Mars conclude that there was once flooding around the Martian equator, and theorize that there are underground deposits of water near the equator. A colony could potentially produce water by tapping into the underground deposits, although it would require extensive testing and mining operations, which would in turn require more energy. Other nutrients are important for human life as well, and present a problem. These elements, such as sodium, zinc, iodine, calcium, and potassium are crucial to the well-being of humans, but are difficult to get on Mars. Calcium and sodium are available in regolith matter such as plagioclase and scapolite, while potassium might be found in lake beds. Zinc deposits are most likely located around volcanoes. Collecting all of these essential minerals from different areas of the planet will be difficult, but iodine and other minerals are not known to exist at all on Mars, and must be imported while the colony is being constructed. Energy production on Mars will undoubtedly be a difficult task. Besides merely producing electricity to power the technical systems of the colony, colonists will have to find energy for themselves in the form of nutrition. They will need to produce the protein, vitamins, and minerals required to live in a hostile environment. However daunting the process might be, the day humans can claim a truly independent colony on a different planet will go down as a new chapter in human history: the conquering of space. Sources: General http://www.redcolony.com/features.php?name=marsfacts Energy requirement estimates http://earthtrends.wri.org/text/energy-resources/variable-351.html Chemical availability in Martian soil http://fti.neep.wisc.edu/neep533/SPRING2004/lecture19.pdf Solar information about Mars http://powerweb.grc.nasa.gov/pvsee/publications/mars/marspower.html